Exponential Capital - Smart Contract Audit Report

Audit Summary

Exponential Capital Audit Report Exponential Capital ($EXPO) is a new ERC-20 token on Ethereum that features automatic liquidity adds and pays dividends to holders.

We reviewed the EXPO and DividendTracker contracts at 0xcFAF8EDCEA94eBAA080DC4983C3f9BE5701D6613 on the Ethereum mainnet.

Audit Findings

The team has successfully completed KYC procedures with KYC Capital.
Date: February 11th, 2022.
Updated: March 14th, 2022 after ownership was transferred to a MultiSig wallet.

Finding #1 - EXPO - Informational

Description: Several functions are declared public, but are never called internally.
			
name, symbol, decimals, increaseAllowance, decreaseAllowance, excludeFromDividends, isExcludedFromDividends, setAutomatedMarketMakerPair, updateUniswapV2Router, updateUniswapV2Router, claim, compound, withdrawableDividendOf, withdrawnDividendOf, accumulativeDividendOf, getAccountInfo, getLastClaimTime, isExcludedFromMaxTx, isExcludedFromMaxWallet, blackList, removeFromBlacklist, blackListMany, unBlackListMany, isExcludedFromDividends
Recommendation: We recommend declaring these functions external for additional gas savings on each call.

Finding #2 - EXPO - Informational

Description: Although the SafeMath library is utilized, the contract is deployed with Solidity v0.8.10 which has built-in overflow checks.
Recommendation: SafeMath could be safely removed to reduce contract size and deployment costs.

Contracts Overview

  • The total supply of the token is set to ~816.72 billion $EXPO [816,722,973,503].
  • No mint or burn functions are present; though the circulating supply can be reduced by sending tokens to the 0x..dead address if desired.
  • At the time of writing this report, 7.63% of the total supply is in Uniswap liquidity.
  • Of that liquidity, 100% of the LP tokens belong to a MultiSig wallet.
  • The next five holders own a cumulative 11.22% of the total supply.

  • There is a tax fee on all transfers via Uniswap where neither the sender nor the recipient is excluded from fees.
  • The fees charged on transfers are stored in the contract and once the threshold number of tokens (determined by the owner) is met, a swap will occur for the purpose of funding Uniswap liquidity.
  • Liquidity-adds are funded by selling a portion of the tokens collected as fees (after the threshold value of tokens is met), then pairing the received ETH with the token, and adding it as liquidity to the ETH pair.
  • The LP tokens received through this process are sent to the Liquidity wallet controlled by the team. We recommend that the team lock these newly acquired LP tokens.
  • The tokens collected from the Treasury Fee are swapped for ETH and sent to the team's Marketing wallet.
  • The tokens collected from the Dividend fee are swapped for ETH and are distributed as dividends in the DividendTracker contract.
  • The contract features a maximum wallet amount which ensures that a user's token balance does not exceed the limit number of tokens (determined by the owner) after a transfer takes place.
  • The contract utilizes the SafeMath library to protect against overflows/underflows along with following the ERC-20 standard.

  • A user must hold at least 10,000 $EXPO tokens to be eligible for dividends.
  • Once dividends are distributed, they can be manually claimed by users at any time.
  • A user can elect to compound their dividends which will swap the amount of ETH dividends due to them for $EXPO tokens and send it to the user's wallet address.
  • There is no wait-time between claiming dividend rewards.
Ownership Controls:
  • The owner can set the Dividend fee, Liquidity fee, and Treasury fee to any percentages at any time.
  • The owner can exclude any address from transfer fees and dividends at any time.
  • The owner can enable/disable transfer fees at any time.
  • The owner can update the threshold number of tokens that triggers the token swapping functionality to any value at any time.
  • The owner can enable/disable the automatic swapping functionality at any time.
  • The owner can add/remove addresses from a blacklist which will prevent them from being able to participate in transfers.
  • The owner can disable a user's ability to compound their dividends at any time.
  • The owner can withdraw any ETH or tokens from the contract address at any time.
  • The owner can set and update a maximum transaction amount to any value greater than 0.75% of the total supply, which will impose a limit to the number of tokens that can be transferred during any given transaction.
  • The owner can exclude accounts from the maximum transaction amount at any time.
  • The owner can update the maximum wallet amount to any value greater than 1.75% of the total supply.
  • The owner can exclude accounts from the maximum wallet amount at any time.
  • The owner can update the team's Marketing wallet and Liquidity wallet to any addresses at any time.
  • The owner can update the Automated Market Maker Pair and Uniswap Router addresses at any time.

External Threat Results

Vulnerability CategoryNotesResult
Arbitrary Storage WriteN/APASS
Arbitrary JumpN/APASS
Centralization of ControlOwnership has been transferred to a MultiSig wallet.PASS
Delegate Call to Untrusted ContractN/APASS
Dependence on Predictable VariablesN/APASS
Deprecated OpcodesN/APASS
Ether ThiefN/APASS
ExceptionsN/APASS
External CallsN/APASS
Flash LoansN/APASS
Integer Over/UnderflowN/APASS
Logical IssuesN/APASS
Multiple SendsN/APASS
OraclesN/APASS
SuicideN/APASS
State Change External CallsN/APASS
Unchecked RetvalN/APASS
User Supplied AssertionN/APASS
Critical Solidity CompilerN/APASS
Overall Contract Safety PASS

Function Graph

BEP20 Token Graph

Inheritance Chart

Multi-file Token

Functions Overview

												
($) = payable function
 # = non-constant function

 +  Context 
    - [Int] _msgSender
    - [Int] _msgData

 +  Ownable (Context)
    - [Pub]  #
    - [Pub] owner
    - [Pub] renounceOwnership #
       - modifiers: onlyOwner
    - [Pub] transferOwnership #
       - modifiers: onlyOwner
    - [Int] _transferOwnership #

 + [Int] IERC20 
    - [Ext] totalSupply
    - [Ext] balanceOf
    - [Ext] transfer #
    - [Ext] allowance
    - [Ext] approve #
    - [Ext] transferFrom #

 + [Int] IERC20Metadata (IERC20)
    - [Ext] name
    - [Ext] symbol
    - [Ext] decimals

 +  ERC20 (Context, IERC20, IERC20Metadata)
    - [Pub]  #
    - [Pub] name
    - [Pub] symbol
    - [Pub] decimals
    - [Pub] totalSupply
    - [Pub] balanceOf
    - [Pub] transfer #
    - [Pub] allowance
    - [Pub] approve #
    - [Pub] transferFrom #
    - [Pub] increaseAllowance #
    - [Pub] decreaseAllowance #
    - [Int] _transfer #
    - [Int] _mint #
    - [Int] _burn #
    - [Int] _approve #
    - [Int] _beforeTokenTransfer #
    - [Int] _afterTokenTransfer #

 + [Lib] Address 
    - [Int] isContract
    - [Int] sendValue #
    - [Int] functionCall #
    - [Int] functionCall #
    - [Int] functionCallWithValue #
    - [Int] functionCallWithValue #
    - [Int] functionStaticCall
    - [Int] functionStaticCall
    - [Int] functionDelegateCall #
    - [Int] functionDelegateCall #
    - [Int] verifyCallResult

 + [Lib] SafeMath 
    - [Int] tryAdd
    - [Int] trySub
    - [Int] tryMul
    - [Int] tryDiv
    - [Int] tryMod
    - [Int] add
    - [Int] sub
    - [Int] mul
    - [Int] div
    - [Int] mod
    - [Int] sub
    - [Int] div
    - [Int] mod

 + [Int] IUniswapV2Factory 
    - [Ext] feeTo
    - [Ext] feeToSetter
    - [Ext] getPair
    - [Ext] allPairs
    - [Ext] allPairsLength
    - [Ext] createPair #
    - [Ext] setFeeTo #
    - [Ext] setFeeToSetter #

 + [Int] IUniswapV2Pair 
    - [Ext] name
    - [Ext] symbol
    - [Ext] decimals
    - [Ext] totalSupply
    - [Ext] balanceOf
    - [Ext] allowance
    - [Ext] approve #
    - [Ext] transfer #
    - [Ext] transferFrom #
    - [Ext] DOMAIN_SEPARATOR
    - [Ext] PERMIT_TYPEHASH
    - [Ext] nonces
    - [Ext] permit #
    - [Ext] MINIMUM_LIQUIDITY
    - [Ext] factory
    - [Ext] token0
    - [Ext] token1
    - [Ext] getReserves
    - [Ext] price0CumulativeLast
    - [Ext] price1CumulativeLast
    - [Ext] kLast
    - [Ext] mint #
    - [Ext] burn #
    - [Ext] swap #
    - [Ext] skim #
    - [Ext] sync #
    - [Ext] initialize #

 + [Int] IUniswapV2Router02 
    - [Ext] factory
    - [Ext] WETH
    - [Ext] addLiquidity #
    - [Ext] addLiquidityETH ($)
    - [Ext] swapExactTokensForTokensSupportingFeeOnTransferTokens #
    - [Ext] swapExactETHForTokensSupportingFeeOnTransferTokens ($)
    - [Ext] swapExactTokensForETHSupportingFeeOnTransferTokens #

 +  EXPO (Ownable, IERC20)
    - [Pub]  #
    - [Ext]  ($)
    - [Pub] name
    - [Pub] symbol
    - [Pub] decimals
    - [Pub] totalSupply
    - [Pub] balanceOf
    - [Pub] allowance
    - [Pub] approve #
    - [Pub] increaseAllowance #
    - [Pub] decreaseAllowance #
    - [Pub] transfer #
    - [Pub] transferFrom #
    - [Ext] openTrading #
       - modifiers: onlyOwner
    - [Int] _transfer #
    - [Prv] _executeTransfer #
    - [Prv] _approve #
    - [Prv] _mint #
    - [Prv] _burn #
    - [Prv] swapTokensForNative #
    - [Prv] addLiquidity #
    - [Prv] includeToWhiteList #
    - [Prv] _executeSwap #
    - [Pub] excludeFromFees #
       - modifiers: onlyOwner
    - [Pub] isExcludedFromFees
    - [Ext] manualSendDividend #
       - modifiers: onlyOwner
    - [Pub] excludeFromDividends #
       - modifiers: onlyOwner
    - [Pub] isExcludedFromDividends
    - [Ext] setWallet #
       - modifiers: onlyOwner
    - [Pub] setAutomatedMarketMakerPair #
       - modifiers: onlyOwner
    - [Ext] setFee #
       - modifiers: onlyOwner
    - [Prv] _setAutomatedMarketMakerPair #
    - [Pub] updateUniswapV2Router #
       - modifiers: onlyOwner
    - [Pub] claim #
    - [Pub] compound #
    - [Pub] withdrawableDividendOf
    - [Pub] withdrawnDividendOf
    - [Pub] accumulativeDividendOf
    - [Pub] getAccountInfo
    - [Pub] getLastClaimTime
    - [Ext] setSwapEnabled #
       - modifiers: onlyOwner
    - [Ext] setTaxEnabled #
       - modifiers: onlyOwner
    - [Ext] setCompoundingEnabled #
       - modifiers: onlyOwner
    - [Ext] updateDividendSettings #
       - modifiers: onlyOwner
    - [Ext] setMaxTxBPS #
       - modifiers: onlyOwner
    - [Pub] excludeFromMaxTx #
       - modifiers: onlyOwner
    - [Pub] isExcludedFromMaxTx
    - [Ext] setMaxWalletBPS #
       - modifiers: onlyOwner
    - [Pub] excludeFromMaxWallet #
       - modifiers: onlyOwner
    - [Pub] isExcludedFromMaxWallet
    - [Ext] rescueToken #
       - modifiers: onlyOwner
    - [Ext] rescueETH #
       - modifiers: onlyOwner
    - [Pub] blackList #
       - modifiers: onlyOwner
    - [Pub] removeFromBlacklist #
       - modifiers: onlyOwner
    - [Pub] blackListMany #
       - modifiers: onlyOwner
    - [Pub] unBlackListMany #
       - modifiers: onlyOwner

 +  DividendTracker (Ownable, IERC20)
    - [Pub]  #
    - [Ext]  ($)
    - [Pub] distributeDividends ($)
    - [Ext] setBalance #
       - modifiers: onlyOwner
    - [Ext] excludeFromDividends #
       - modifiers: onlyOwner
    - [Pub] isExcludedFromDividends
    - [Ext] manualSendDividend #
       - modifiers: onlyOwner
    - [Int] _setBalance #
    - [Prv] _mint #
    - [Prv] _burn #
    - [Pub] processAccount #
       - modifiers: onlyOwner
    - [Prv] _withdrawDividendOfUser #
    - [Pub] compoundAccount #
       - modifiers: onlyOwner
    - [Prv] _compoundDividendOfUser #
    - [Pub] withdrawableDividendOf
    - [Pub] withdrawnDividendOf
    - [Pub] accumulativeDividendOf
    - [Pub] getAccountInfo
    - [Pub] getLastClaimTime
    - [Pub] name
    - [Pub] symbol
    - [Pub] decimals
    - [Pub] totalSupply
    - [Pub] balanceOf
    - [Pub] transfer
    - [Pub] allowance
    - [Pub] approve
    - [Pub] transferFrom